Cadarn magi are a type of elf that can be fought in the Cadarn clan district of Prifddinas. They can use abilities against the player in combat. Their adrenaline works differently to that of players - it starts at 50%, and never changes. This means they can always use threshold abilities, but never ultimates. Their adrenaline can be Siphoned or drained by Leech Adrenaline, but it doesn't affect their ability to use thresholds. These elves do not die when their life points reach zero; instead, they kneel on the ground, drop some items and say "I am bested. I commend you." Since they never actually die, debuffs like Quake, Goliath Gloves, Ancient Curses and formerly Storm Shards remain when they are on the ground.

Defeating a combined 1,000 Cadarn magi/rangers unlocks the title [Name] of the Cadarn, which is a Completionist cape requirement.
Players can check how many Cadarn magi/rangers have been defeated so far in the Titles interface by clicking on the title 'of the Cadarn'. The number of defeated Cadarn magi/rangers will appear on the bottom right.

There is currently a glitch where Cadarn magus occasionally attack the player while they are defeated.

For a while after the release of Prifddinas, the magus' Asphyxiate was the early EoC version of the ability, which stunned players rather than binding them which the version available to players did at the time. The stun effect was removed due to player complaints. However, they were later returned when the Asphyxiate ability was changed back to stunning, though it now applies a 3.6 second stun and a 6 second bind rather than a 6 second stun and bind.